Stomach cancer, which is also known as gastric cancer, is a type of cancer that forms in the inner lining of the stomach. Reports suggest that about 1 million stomach cancer cases are recorded every year throughout the world. It is more common in the Southeast Asian region.
Smoking, chronic Helicobacter pylori infection and consumption of salty and spicy food are some of the factors that increase one’s risk of developing stomach cancer.
Based on the type of tissue that they originate from, stomach cancers are classified into:
- 1. Adenocarcinomas: Around 90 – 95% of stomach cancers are found to be adenocarcinomas. These start in the innermost lining of the stomach called the mucosa.
- 2. Gastrointestinal stromal tumours (GISTs): These tumours form in the interstitial cells of Cajal of the stomach wall and are of rare occurrence.
- 3. Neuroendocrine tumours: Neuroendocrine tumours are slow-growing tumours that arise from the neuroendocrine cells. These are slow-growing tumours and rarely spread to other organs.
- 4. Lymphomas: Lymphomas are another type of stomach cancer that involves the lymphatic system.
Other rare cancers of the stomach include gastric sarcomas, small cell carcinomas, squamous cell carcinomas and leiomyosarcomas.
The signs or symptoms are not very clear in the early stages of the disease. However, as the disease progresses, the following symptoms are observed:
- Feeling full after a small meal
- Indigestion or stomach discomfort
- Loss of appetite
The above symptoms could also indicate a peptic ulcer, which needs immediate medical attention as chronic ulcers are one of the risk factors for stomach cancer. As stomach cancer advances, the following symptoms are observed:
- Discomfort in the stomach (upper and middle region)
- Blood in stool
- Vomiting (with or without blood)
- Unintentional weight loss
- Pain after eating
- Fatigue as a result of having a low RBC count
The exact cause of stomach cancer is unknown. However, there are a few risk factors that are associated with stomach cancer:
- Helicobacter pylori infection: H.pylori is a bacterium that infects the stomach lining and causes chronic inflammation and ulcers. If left untreated, it may lead to stomach cancer.
- Gender: Stomach cancer risk is higher among men than women.
- Age: The risk of developing stomach cancer increases with age.
- Genetics: Inherited cancer syndromes, such as Hereditary diffuse gastric cancer (HDGC), Lynch syndrome, Familial adenomatous polyposis, Li-Fraumeni syndrome, Gastric adenoma and proximal polyposis of the stomach and Peutz-Jeghers syndrome increase of risk of stomach cancer development.
- Lifestyle Factors: Poor lifestyle habits, such as smoking, drinking alcohol, intake of salted, smoked or nitrate-preserved foods, reduced intake of fruits and vegetables, etc., contribute to the increased risk of stomach cancer development.
- Race: Stomach cancer risk is high among the populations of Hispanic Americans, African Americans, Native Americans and Asian (Southeast Asia) ethnicity.
- Family History of the Disease: Those with a positive family history of stomach cancer have a higher risk of the disease.
- Blood Type: Those with blood type ‘A’ have a higher risk of stomach cancer.
- Exposure to Harmful Chemicals: Individuals involved in occupation like nickel refining, coal mining, rubber and timber processing show a higher risk of developing stomach cancer. Asbestos exposure is considered a risk factor too.
- Certain Health Conditions: Certain health conditions, namely pernicious anaemia, chronic gastritis, intestinal metaplasia, gastric polyps and prior stomach surgeries, are associated with an increased risk of stomach cancer.
There are multiple test methods available to detect and diagnose stomach cancer:
Physical Examination and Blood tests are carried out to check for any abnormalities, and if stomach cancer is suspected, the following tests may be recommended for a definitive diagnosis:
a. Endoscopy: During endoscopy, the doctor passes a thin, lighted tube that is fixed to a camera through the throat to examine the regions of the oesophagus, stomach and the upper part of the small intestine.
b. Biopsy: Biopsy involves the removal of a small portion of the tissue from the suspected area and its examination under the microscope. A biopsy helps in arriving at a definitive diagnosis with crucial information such as the nature of the tumour, its grade and stage.
c. Imaging Tests: Imaging tests such as PET/CT scans, MRI scans, barium swallow, X-rays, etc., help in determining whether or not cancer has spread to surrounding organs. The results of tests also help in treatment planning.
Stomach cancer is one of those cancers that become apparent in the advanced stages. Therefore, any symptom that persists for more than two weeks should not be ignored. Stomach cancers are usually treated with surgery, chemotherapy and radiation therapy.
a. Surgery: During surgery, the tumour and a small portion of healthy tissues surrounding it are removed. Depending on the location and the stage, part of the intestine, pancreas or other affected organs may be removed as well.
- Endoscopic Mucosal Resection: This is a minimally invasive surgery where the tumour is removed using an electrical wire loop during an endoscopy. This method is effective and is opted for early-stage stomach cancers where the tumour has not deeply grown into the wall.
- Endoscopic Submucosal Dissection: This procedure is similar to mucosal resection, but it is used to resect a larger area of mucosa in one piece.
- Partial Gastrectomy: Partial gastrectomy involves the removal of a portion of the stomach where the tumour growth is seen. This procedure may be recommended if the tumour growth is seen in the upper part of the stomach (proximal gastrectomy) and the lower part of the stomach (distal gastrectomy). If cancer has spread to the spleen and other surrounding organs, those are removed too.
- Total Gastrectomy: During total gastrectomy, the entire stomach is removed along with other organs that are affected by cancer. Later, the oesophagus is directly attached to the small intestine. Patients who have undergone this procedure can eat in small quantities only.
- Palliative Surgery: Surgeries are also performed as a part of palliative care. The intent of palliative surgery is to control cancer and ease symptoms such as pain.
b. Chemotherapy: Chemotherapy may be administered before the surgery to shrink the tumour size or after the surgery to destroy the cancer cells that are left behind. In advanced-stage cancers, chemotherapy may be the main line of treatment as a part of palliative care. Chemotherapy helps in shrinking the tumour size, alleviating pain and other symptoms and increasing the lifespan of the patients.
c. Radiation Therapy: This treatment uses high-energy radiation beams to destroy the tumour cells and stop their growth. Radiation therapy is often delivered in combination with surgery or chemotherapy.
Frequently Asked Questions
1. Can omeprazole hide stomach cancer symptoms?
Omeprazole medication belongs to the class of proton pump inhibitors (PPIs) that are used to treat conditions like dyspepsia and acid reflux.
It has been found that omeprazole and other PPIs can alter the symptoms of stomach cancer and lead to delayed diagnosis.
2. Does stomach cancer always return?
Not always, but stomach cancer does return in a few cases, and it is called recurrence. Based on the stage of the disease and the overall condition of the patient, treatment planning is made and the disease is managed.
3. Is stomach cancer hereditary?
Yes, in a few cases, stomach cancer is hereditary, and having one or more close relatives with stomach cancer increases your stomach cancer risk.
4. Why is stomach cancer more common among Southeast Asians?
High rates of Helicobacter pylori infection and increased consumption of salted and smoked food are the two main factors that contribute to the increased cases of stomach cancers among Southeast Asians.
5. How to prevent stomach cancer?
A good number of risk factors that are associated with stomach cancer are preventable. Following are few preventive measures that can help you reduce your stomach cancer risk:
- Healthy weight management: Maintaining a healthy weight is important to reduce your stomach cancer risk.
- Consumption of nutritious food: Diet rich in vegetables and fruits helps in reducing your risk of developing stomach cancer.
- Reduced intake of salted and smoked food: A balanced diet brings your stomach cancer risk down.
- Quit smoking: Quit smoking to reduce your stomach cancer risk.